Unfortunately, this is insufficient information for me to offer any help to either problem. Your first post shows an apparent video issue, the second post an apparent bootloader issue. That is all that I can perceive.

I operate an OpenBSD/amd64 server in a KVM virtual machine through a commercial cloud service (vultr.com), and have been a customer for about a year. I have not experienced any operational issues with the virtual machine. However, there are two key differences:

I do not run an X server.

I am remote, as this is a VPS. The virtual machine console is connected via a noVNC connection to my browser.